Air conditioning device and control method thereof

Abstract

The invention relates to an air conditioning device and a control method thereof. The air conditioning device comprises a compressor, a four-way valve, an indoor heat exchanger, a sleeve pipe heat exchanger, an expansion valve and an outdoor heat exchanger. The control method comprises the steps that when the air conditioning device carries out heating operation till the outdoor heat exchanger needs to be defrosted, whether the outdoor environment temperature is within the range of a preset temperature interval or not is judged, and if yes, a down-flow defrosting mode is started; in the down-flow defrosting mode, the state of the four-way valve is kept unchanged, the expansion valve is promoted to be totally opened, whether the temperature of a coil pipe of the indoor heat exchanger is larger than or equal to a first preset temperature or not is judged, and if yes, an indoor fan is started; and if no, the indoor fan is stopped, the coil pipe of the indoor heat exchanger is heated, andafter the temperature of the coil pipe of the indoor heat exchanger reaches or exceeds the first preset temperature, the indoor fan is started. The technical problem that in the existing defrosting process, the indoor temperature fluctuation is large, and consequently comfort is poor is avoided; the defrosting time is shortened; noise is reduced; and operation stability is improved.

Description

technical field [0001] The invention relates to common electric appliances, in particular to an air conditioner and a control method thereof. Background technique [0002] In the case of low temperature and high humidity, if the air conditioner operates in heating mode for a long time, the water vapor in the air will condense and freeze on the surface of the outdoor heat exchanger or directly condense into frost crystals. As time goes by, the frost crystals will become thicker and thicker, which will hinder the air convection heat transfer of the outdoor heat exchanger, resulting in a lower surface temperature of the outdoor heat exchanger, deterioration of the heat transfer effect, and rapid attenuation of heating capacity. At this time, it is necessary to defrost the outdoor heat exchanger. [0003] Conventional air-conditioning defrosting is two ways: countercurrent forced defrosting and thermal storage defrosting. Thermal storage defrosting mainly uses thermal storage ...

AI Technical Summary

Problems solved by technology

The forced reverse flow defrosting process includes two start and stop of the compressor, two reversing of the four-way valve, waiting time for system pressure balance, and anti-cold wind protection time after exiting defrosting, etc., resulting in a long duration of the entire defrosting process

Moreover, during the above-mentioned defrosting process, the indoor fan of the air conditioner is in a stopped state, resulting in a low temperature of the indoor refrigerant, and the increased cooling load of the defrosting and the cooling load of the wall make the indoor temperature drop sharply, and the indoor temperature fluctuates greatly, which in turn causes people The problem of poor comfort

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